Electromagnet.



No. 843,919. PATENTED FEB. 12, 1907. J. E. WASHBURN.

ELEOTROMAGNET.

APPLICATION FILED JULYZB, 1906.

q/Vmwomv "@udawn.

UNITED STATES PATENT @EETGE.

ELECTROMAGNET.

Specification of Letters Patent.

Patented Feb. 12, 1907'.

Application filed July 28,1906. Serial No. 828,173.

To 60M 10/7/0771, it may concern:

Be it known that I, J OHN E. WAsnBUuN, a citizen of the United States, and resident of Egmont, Hillsborough county, State of Florida, have invented certain new and use ful Improvements in Electromagnets; and my preferred manner of carrying out the invention is set forth in the following full, clear, and exact description, terminating with a claim particularly specifying the novelty.

This invention relates to electromagnets, and especially to the cores employed therein.

Heretofore it has been common to make the core of an electromagnet of a soft-iron rod or bar in one piece, surrounded by the coils or convolutions of the insulated wire, and to make the armature of said magnet of another piece of metal arranged in pivotal or movable relation to the core, and. for certain purposes it has been found desirable to make the core of laminated material or composed of a number of wires in longitudinal parallelism and in metallic and electric connection with each other.

The present invention contemplates a radical change in the arrangement of parts, to the extent that the core of the electromagnet is in itself longitudinally expansible and contractible, and hence the armature may be fixed or it may have a limited degree of movement.

The gist of the invention consists in makin g the core of a series of metallic disks (preferably of soft iron) which are preferably normally out of close contact with each other, but so arranged that they may move under the influence of the electric impulse, as described below.

To this end my invention consists in the use, in an electromagnet, of a core composed of disks and preferably arranged as shown in the accompanying drawings, wherein* Figure lis a longitudinal sectional view of an electromagnet embodying the use of my improved core. Fig. 2 is a side elevation of the core itself before the electric impulse is applied. Fig. 3 is an edge view of one of the disks of said core, showing the thinner and thicker parts thereof. Fig. 4 is a sectional view of a modification in which the resilient connecting devices are omitted. This view also shows in dotted lines how a bell-clapper could be carried by the flexibly-supported armature.

In the accompanying drawings I have shown a spool (consisting of two heads H and a tubular shank T) which forms one important part of an electromagnet, and the letter I designates the insulated wire wound on said shank between the heads. As customary in devices of this character, when an electric current is passed through said coil of wire I the soft-metal core contained within the shank T becomes a magnet. The present invention consists in making said core out of number of disks connected at two or three points at their edges by rubber bands It or other devices which are not under tension, and therefore ordinarily hold each disk out of contact with the adjacent disk, but which permit the contact of the same when they are drawn together by any force. Thus it will be possible to substitute springs for the rubber bands it, and the latter are therefore claimed in this case as resilient connecting devices, because that is their function. The disks are imperforate, an d their larger and thinner portions fit loosely and are guided within the tubular shank T. By preference one of the disks is secured by a screw S to one of the heads H, thence the stack of disks extends loosely through the tubular shank T and the most remote stands adjacent the armature A.

If this device is to be used as a telegraphic instrument, the armature A may be fixed, and the approximation. of the various di 1 will cause a click as they come together, which will take the place of the noise usually made by the armature as it moves between its points, a similar click being made as they separate, and the outermost disk strikes the similar noise usually made by the opposite movement of the armature. However, it is quite possible to employ a movable armature in connection with this improved electromagnet-core, and I therefore do not limit myself strictly to a faxed armature, although the same is ordinarily sufficient where tne core itself is expansible and contractible in length. In the construction herewith illus trated I have shown each disk as composed of a thick body portion 1) and a thinner portion (Z, the latter being of greater diameter, so as to constitute a flange, and all flanges stand l relatively at the same side of their respective body portions. These flanges are shown as connected at two or more points longitudinally of the stack of disks by rubber bands R armature, thereby taking the place of theor other equivalent resilient connecting devices which will permit their relative move ment and which, in eilcct, will permit tire approximation and divergence of the various disks. It is possible that all such con necting devices may be dispensed wit-r, as snown in Fig. 4, in which case tire wi-zler portions or 'l'langes or the disks would slide longitudinally witnin the tubular shank 'l. of 't e spool, and I therefore do not lixnit 111: self strictly to tie use of any such connecting means, although I consider it advantageous. The material of which the disks is composed is not important, excepting that it should be one which when acted upon electrically will cause the disks to be approximated and when the surrounding coil is denergized will cause the disks to be robbed of their mutually attractive property, the broad idea being that when the current "Hows the disks wil be approximated and the one farthest remote 'i'rozn the screw S will be drawn away from t. e armature A; but when the current is shut oil the disks will be separated or repelled from each other, (though possibly be neld in alincment by tie connecting means 11,) and the one remote from the screw S may make metallic contact with the armature A.

The uses to which this electromagnet may be put are many; but I do not consider it necessarily within the province of this specification to enumerate them. It the stack of disks is long, although the movement between each two of then is trifling, it will be clear that the movement of the outermost disk away from tne armature will be considerable, varying only with the numb er of disks in the stack and the degree of movement between them. Hence it is possible to e'rnploy this device, for instance, in an annunciatorbell and in a circuit men is extremely weak. Perhaps I should not say that tne armature is absolutely fiXOtl, because in an annunciatorbell where the clapper is attached to the armature the latter ordinarily vibrates, so as to ring the bell; but it will be clear that witn an ex pansible and contractible core an armature can be employed wnose movements are so trifling that it need not be pivoted."may only, in fact, have to be flexibly connected witn its support, as shown in Fig. i, so that the bell-clapper C at its otner extretnityean vibrate to a sufficient degree to scum. an alarm. In a word, the principal advantage attained by this invention may be said to consist in the use of a 'l'lexibly-niounted armature with a limited degree of nioveinent instead of a pivoted armature, the expansibib it y and contractibility of the core of the electro-magnet taking the place of the movement which tne armature does not have.

hat is claimed as new is 1. An electromagnet whose core is composed of a series of iinperlorate disks, each having a thick and a thin portion or diilerent diameter.

2. An electromagnet whose core is composed of a series of imperiorate disks, each having a thick body of smaller diameter and a thin lla-nge oi larger diameter.

3. An electron'iagnet comprising a spool havin a tubular shank wound with insulated wire, and a core composed of a series cl? iinperi erate disks, each having an enlarged llange loosely mounted and guided within the tubular shank of said spool.

I. An electromagnet comprising a spool having a tubular shank wound with insulated wire, and a core composed ol a series of disks each having a portion. of smaller diameter and a portion of larger diameter, the latter 'i'itting and guided within the tubular shank of the spool and all the disks standing in the same position relatively to each other.

5. An electromagnct whose core is composed of a series ol disks which are norn'ially slightly out oi contact with each other, rcsilient connecting devices along the edges oi said series, a fixed support l or the disk at one end of the series, and an armature adjacent to but disconnected from the disk at the other end.

6. An eleetromagnet whose core is composed of a series of disks which are normally slightly out of contact with each other, resilien't connecting devices along the edges of said series, a 'lixed support for the disk at one end of the series, and a flexibly-mounted armature at the other end.

7. In an electromagnct, the combination with the heads connected by a tubular shank, and the insulated wire wound around the lat ter; of an armature consisting of a series ol disks each composed of a thicker portion. of smaller diameter and a thinner portion of larger diameter, the parts being in the same position relatively to each other and the pertions of larger diameter iitting loosely within said shank, resilient connecting devices extending longitudinally of the series and. connecting the parts of larger diameter, a screw connecting the disk at one end of the series to one of said. heads, and an armature at the other end of the series.

8. In an electromagnet, the combination with the heads connected by a tubular shank, and the insulated wire wound around the latter; of an armature consisting of a series of disks each composed of a thicker portion oi smaller diameter and a thinner portion ol larger diameter, the parts being in the same position relatively to each other and the pertions of larger diameter 'l'itting loosely within said shank, longitudinal rubber bands connecting the edges oi said parts of larger diameter, means for attaching the disk at one end to one of said heads, and an armature at the other end oi the series.

9. In an electroinagnet, the combination l eter, means for attaching the disk at one end with the heads connected by a tubular shank, l to one of said heads, and a flexibly-mounted and the insulated Wire Wound aroiii'id the latarmature at the other end of the series. ter; of an armature consisting of a series of l In testimony ix hereol l have hereunto suh- I5 disks each composed of a thicker portion of scribed my signature this the 14th day 0'! smaller diameter and a thinner portion of July, A. D. 1906. larger diameter, the parts being in the same JOHN E NA SHBURN posltion relatively to each other and the portions of larger diameter fitting loosely Within \Vitnesses: said shank, longitudinal rubber bands con- 1 HARRY P. BAYA, necting the edges of said parts of larger diani- CLARENCE 0. LOVE. 

